When you play an instrument, (depending on what instrument you're playing) they normally don't require a muscle movement. Think of the types of instrument, wind, string, etc. Do they need a lot of muscle movement?

For most music instruments you don't need very much muscle strenght. and certainly not as much as an athlete does. Playing a music instrument is mostly a brain thing, not an activity that requires strenght. So i'd say the statement is false.

yes, you also use muscles to play music instruments but your statement says that musicians need to train their muscles in order to play an instrument, which is of course false. There might be a few instruments where you needs muscle strenght for but that would be irrelevant because the main part of the instruments don't require much strenght.